So the slow cooling with the oven cracked...this is a technique that I personally love for so many things. Slowly bringing the temperature down on something so light and airy is really a deal breaker. You of course can take your chances and pull them straight out of the oven to cool, I have many times. Sometimes they cool perfectly fine, no problem. But sometimes they come out looking perfectly and I turn my head and they sink...all that light airiness dissipates. And while I know this is an extra step that can seem annoying, it absolutely yields the perfect cupcake every time. And I mean, chances are, you're not baking these and literally running out the door, so the half hour of gentle cooling won't be killing you anyways :)